We have an application deployed on a Fly instance that is intermittently not receiving broadcasts from Phoenix PubSub. On our development machines nothing is missed, on Fly, it’s random, but at least 50% of the messages that are broadcast are not picked up by the subscription. In addition it’s not certain subscriptions that are failing, it’s random there too.
As far as I can tell we have a vanilla PubSub implementation, and our Fly install is standard other than we are connectiong to an external database on CrunchyBridge. Our Fly install is running on two machines “shared-cpu-1x”.
I’m posting here as it feels like a network issue, and I’m hoping someone has some ideas about where we can look to troubleshoot this further.
Thanks in advance.
EDIT I should add to this that there are no errors being shown.